Simulation of Electrolyte Absorption

Abstract:

THE GROWTH OF DAPHNIA AND THE STUDY OF THE EFFECT OF ELECTROLYTE ABSORPTION ON CELLULAR RESPIRATION. Jeremy Tong. The purpose of this lab was to grow Daphnia organisms and sustain them in a monitored solution and also to observe the effect of electrolyte absorption on the function of a Daphnia’s heart. To accomplish this, the experiment was split into two specific parts, the first of which was in sustaining a living population of Daphnia, and the second was creating an electrolyte solution that would affect but not kill the Daphnia. In the first part of the experiment, it was determined that smaller 1.0 L containers with a food source of yeast yielded the best results in the survival of the Daphnia. The results of the first part of the experiment support the fact that Daphnia respond sensitively to their environment, and helped reinforce the results of the second part of the experiment. In the second part of this experiment, solutions of different molarity of potassium nitrate were dropped along with a Daphnia in a Petri dish. Solutions above .1 molar concentrations caused the Daphnia to die within five minutes. However, the solutions did not have any notable effect on the Daphnia heartbeat. The only concentration in which Daphnia survived greater than the five minutes allotted was when a .05 Molar Solution was used. Coming back to the lab in May, more data was collected using a .05 and .075 Molar solution. The trend of a drastic heartbeat increase at the initial adding of the solution, followed by a slow increase, and then an abrupt death was found in multiple tests across Daphnia of different sizes. Because it was discovered that potassium ions in the heart lower heart rate by blocking calcium channels, an explanation of the trend found in Daphnia could be attributed to the attempt to maintain homeostasis. The Daphnia swam around frantically to increase its heartrate to counteract the forces of the potassium ions, but this coping mechanism was eventually overcome as the Daphnia heart rate gradually increased, and then abruptly stopped. The point of the Daphnia death was perhaps the result of the Daphnia not being able to maintain homeostasis and transfer oxygen throughout its body. Thus, electrolytes do not truly benefit the cellular respiration in Daphnia in higher concentrations of ions, and perhaps do not reflect electrolyte absorption affects on the human .

Daphnia, Electrolyte Absorption, Cellular Respiration, Diffusion across Membrane

Figure 1: Daphnia Containers

Container 1: 1.0 L yeast solution	Container 2: yeast + algae 10 L Solution
Container 3: 1.0 L algae Solution

Figure 2: Dissecting Microscope


Figure 3: Daphnia under Microscope








Table 1: Heartbeat of Daphnia and Observations

	Size of Daphnia	Concentration of KNO3 Solution (M)	Heartbeat per Minute	Dead/Alive after five min	Observations
Control 1	Large	0	156	Alive	Heartbeat is steady, Daphnia is relatively still
Control 2	Large	0	162	Alive	Heartbeat is steady, Daphnia is still
Control 3	Small	0	195	Alive	Heartbeat is quick and steady, Daphnia has minor movement
Control 4	Small-Medium	0	180	Alive	Daphnia moves slowly
Trial 1	Large	1.0	5 min = 0	Dead	Daphnia appears extremely irritated and jolts back and forth under stress in solution
Trial 2	Medium	0.1	2 min = 198 5 min = 0	Dead	Daphnia still seems as irritated and jolts similarly to Daphnia in 1.0 M solution
Trial 3	Small	0.1	Before = 183 2 min = 180 5 min = Dead	Dead	Daphnia is irritated and dies, heartbeat does not change after solution is added
Trial 4	Small	0.05	Before = 150 2 min after = 159 5 min after = 159 bpm	Alive	Daphnia seems less irritated and survives for five minutes while submerged in solution. Heartbeat does not show any major changes throughout

Table 2:
May Data on Daphnia Heartrate

Trial #	Size of Daphnia	Concentration of KNO3 Solution (M)	Heartbeat per Minute at 0 min	Heartbeat after solution is added	Time of Death (minute)	Observations
1	Large	.05	165	3 min = 183 4 min = 180 6 min = 174	10 min	1 min = swimming around frantically 2 min = swimming around frantically 3 min = swimming around frantically 4 min = Struggling less 6 min = Stopped Moving
2	Medium	.05	-	1 min = 177 3 min = 171	5 min	1 min = swimming around fast 3 min = kicking a lot, trying to move 4 min = begins to move slower
3	Small	.05	189	2 min = 189	4 min	0 min = moving/acting normal 2 min = moving faster
4	Large	.05	177	2 min = 180 5 min = 176	-	0 min = moving slowly/slugglish 2 min = visible sign of internal movement in the Daphnia – seems like digestion or babies
5	Small	.05	183	2 min = 171 4 min =156	6 min	0 min = normal 2 min = not swimming much 4 min = Seems subdued by environment
6	Small	.075	165	2 min = 171 4 min = 177	-	0 min = normal 2 min = swimming frantically 4 min = staying alive but is moving relatively fast
7	Small	.075	169	2 min = 153 4 min = 135	6 min	0 min = Acting normal 2 min = Swimming normally, not frantic at all 4 min = Struggling for movement, seems to be dying
8	Very Small	.075	171	3 min = 177	5 min	0 min = Normal 3 min = Slowing down
9	Medium Small	.05	183	2 min = 207 4 min =156	6 min	2 min = Swimming Frantically 4 min = Very slow movement

References:


Shi, X., & Passe, D. H. (2010). Water and Solute Absorption From Carbohydrate- Electrolyte Solutions in the Human Proximal Small Intestine: A Review and Statistical Analysis. International
University of Maryland. (2011, July 10). Potassium. Retrieved from http://www.umm.edu/altmed/articles/potassium-000320.htm